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在单轴压力下对辉长岩、大理岩等岩石破裂过程中产生的电、磁、声信号作了实验研究。实验分干、湿两种情况进行, 测试系统的频响范围为超低频。主要结果是:获得了岩样从受压到解体过程中, 在0-20kHz频段内的电磁辐射和声发射信号的原始波形;岩石破裂过程中电磁信号的辐射强度与岩石的岩性、含水量、破裂强度、加载率和破裂状态有关;岩石破裂过程中的电磁辐射率和声发射率有关系, 它们的最大值在时间上相对应的约占70%,而且电磁辐射信号比声发射信号发育, 持续时间也较长;实验中以铜板天线为接收传感器的电磁信号的主能潜在6kHz以下, 而以电感线圈为接收传感器的电磁信号主能谱在10kHz左右, 声发射的主能谱在3kHz以下;声发射信号出现之前有明显的电磁信号。由于岩石在破裂过程中辐射的电磁信号与声发射有较好的对应关系, 因此可以认为, 岩石破裂实验中获得的电磁辐射信号与岩石破裂有密切的关系。所以, 地震前观测到的电磁辐射异常主要是由岩石的破裂引起的。至于实验中在声发射之前出现的电磁信号, 则可能与压电、压磁效应有关。 相似文献
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SF-1型岩石声发射测试仪是岩石力学实验研究的一种非常有用的测试仪器。它可以用来监测岩石或岩石样品在外力作用下,发生变化过程中由微破裂所产生的声发射现象。它不仅可以研究微破裂与应力、变形、波速、时间等的变化规律,而且还可以进一步研究微破裂与主破裂(大破裂)的关系。所以它在岩石或岩体的变形破坏实验研究中具有重要的意义。多年来,在进行岩石力学研究中一直缺少适用的声发射仪,从而影响了这方面工作的开展。为了当前 相似文献
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用几种不同加载方式对岩石样品进行了单轴压力实验。以恒定应变率(约为10-5)对样品加载时,岩石的破裂过程大致可分成四个阶段:孔隙压缩阶段、弹性变形阶段、体积膨胀阶段和临震阶级。后二个阶段显著的特点是岩石开始表现出非弹性的体积应变并在主破裂前急剧增大,它与微破裂累积总数二者存在着同步的变化。在重复加载时,发现岩石的微破裂过程具有不可逆的性质,这种现象似乎可以用来说明同一地区短期内发生的两次地震的地震序列的不同,指出运用历史地震资料时应注意该地区应力变化的历史情况。 相似文献
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运用岩石破裂过程分析RFPA^2D系统．研究了岩石介质宏观非均匀性（含裂纹）对宏观力学行为和微震序列类型的影响。通过对5种不同岩石介质结构的宏观非均匀性样本进行破裂过程的数值模拟,发现非均匀程度不同会产生不同地震序列类型,主要有：前震-主震-余震型、主震型和震群型。此外,对5种不同均质度系数的岩石样本破裂过程的模拟。结果表明,岩石介质结构的宏观非均匀性不仅对岩样宏观强度和宏观变形非线性行为有显著的影响,而且也显著地影响试样破裂模式。随着非均匀程度的降低,主破裂呈现脆断模式,而随着非均匀程度的增加而呈现韧性破坏特征。 相似文献
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设计了采用非接触方式、高放大倍数、高效率的电荷传感器,并给出了电荷传感器的设计原理和技术指标。利用研制的电荷传感器对岩石变形破裂过程中产生的电荷感应信号进行了检测试验。结果表明,岩石在变形破裂过程中会产生电荷感应信号,并能够被研制的电荷传感器检测到;电荷感应信号是瞬时脉冲的;随着加载应力水平的增加,电荷感应信号强度增强,在峰值应力前,电荷感应信号强度达到最大值;在破裂面接收到的电荷感应信号较强,主破裂面接收到的信号最强,因而电荷的产生和岩石的破裂有很大的关系。作为正在探索的检测岩石破坏过程的手段之一,电荷感应方法应是一种很具潜力的方法,值得深入研究。 相似文献
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在岩石加载直到破裂的过程中,对岩石的红外辐射进行了遥感观测研究.使用的主要仪器有瞬态光谱仪、智能光谱仪、红外辐射温度计、红外光谱辐射计和红外热象仪.对26种岩石进行了实验.研究表明,岩石的红外辐射温度随应力的增加而增加;岩石的红外辐射波谱的幅值也随应力的增加而增加.岩石的红外热象的观测结果与岩石的红外辐射温度相一致.某些岩石样品破裂主断层形成前,在未来主断层的位置显示出条带状温度异常热象.本实验将遥感学中的最新技术引入岩石力学,以期在岩石力学中建立一个新的研究领域遥感岩石力学(或遥感岩石物理学).遥感岩石力学可望在地震预报,岩爆预报和岩体应力场的测量中得到应用. 相似文献
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1 研究背景
声发射是指岩石在受力过程中发生变形和破裂,其应变能释放所监测到的一种物理现象,而b值是表征地震震级—频度关系的参数,研究人员发现,b值具有非线性特征,且与岩石破裂过程密切相关.因此,利用岩石试件变形破坏过程中产生的声发射事件模拟地震,进而研究不同加载条件下岩石变形破坏过程中的声发射b值变化特征,可用于监测岩石受力破坏过程中内部预存微裂隙的活动状态,有助于揭示岩石损伤机理及岩石的破坏程度,也可作为岩石失稳预警参数,捕捉地震发生的前兆信息. 相似文献
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运用岩石破裂过程分析RFPA2D系统，研究了岩石介质细观非均匀性对宏观力学行为的影响和微震序列特征. 通过对不同均质度系数m=1.1，1.5，2，3，5的5个样本进行破裂过程的模拟，发现均质度不同会产生不同地震序列类型，主要有：前震-主震-余震型、主震型和震群型. 此外，对5种不同均质度系数的岩石样本破裂过程的模拟表明，岩石介质的非均匀性不仅对岩样宏观强度和宏观变形非线性行为有显著的影响，而且也显著地影响试样破裂模式. 随着均质度系数的提高，主破裂呈现脆断模式. 同时介质的细观结构随机性，也对试样宏观破裂模式产生重要影响. 相似文献
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《地震学报(英文版)》1996,9(3):447-454
In order to investigate the physical mechanism of seismo-electromagnetic signals, many scholars from China and other countries
have carried out laboratory and field experiments of rock samples by loading them up to fracture in recent ten-odd years.
In each of these experiments, the phenomenon of electromagnetic radiation was observed during the process of rock sample fracture.
However, the experimental results can not explain the non-synchronous electromagnetic radiation in actual observation records.
In these records, some stations displayed anomalies but some others did not, and the signals of different frequency bands
observed by the same station did not occur simultaneously. This has brought about many difficulties to the application of
electromagnetic radiation in earthquake prediction. The experimental result of this paper can explain the phenomenon of non-synchronous
electromagnetic radiation. In the experiment of this paper, rock samples are uniaxially compressed up to fracture. The antennas
of different frequency bands are installed two meters away from the rock sample in different directions. The electromagnetic
signals during the whole process of rock sample fracture are recorded synchronously by a 14-channel tape recorder. The experimental
results are as follows: (1) signals of the four frequency bands: VLF, MF, HF and VHF, are all recorded during the main fracturing
process of rock samples, but signals of different frequencies may somtimes occur non-synchronously; (2) the intensity of electromagnetic
radiation is the highest at the moment when the main fracture occurs, but signals in different directions are of different
intensities. The above results are consistent with the non-synchronous electromagnetic radiation observed in real earthquakes.
It seems possible to predict the orientation of future seismic source by the electromagnetic method of the LF or VLF frequency
bands.
Contribution No. 95A0075, Institute of Geophysics, SSB, China.
The paper is translated by Prof.Jie-Fan HUANG, Peking University from the Chinese into English version. 相似文献
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The results of hardware and methodological developments for recording of electromagnetic emission (EME) generated by rock
samples under loading in laboratory experiments are presented. The results of experiments with the instruments developed are
described. The facilities developed made it possible to measure reliably the electromagnetic emission under conditions of
high background of electromagnetic noise and to reduce the level of reliably recorded signals as compared with previous experiments.
The results of observation of the appearance of electromagnetic emission in the experiments with the rock samples under laboratory
conditions showed a high correlation of the time instants of generation of the electromagnetic emission and the changes of
its parameters with the changes in the reactive resistivity of the rock sample and seismoacoustic emission activity in the
controlled area of the sample. It is revealed that electromagnetic emission occurs and reaches its maximum on the descending
branch of the plot of polarizability during rock destruction. 相似文献
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Experimental study on the mechanism of non-synchronism of seismo-electromagnetic radiation precursors 总被引：1，自引：0，他引：1
ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｒｏｕｇｈ２０－ｏｄｄｙｅａｒｓ’ｏｂｓｅｒｖａｔｉｏｎａｎｄｓｔｕｄｙａｆｔｅｒｔｈｅ１９７６Ｔａｎｇｓｈａｎｇｒｅａｔｅａｒｔｈｑｕａｋｅ,ｔｈｅｓｅｉｓｍｏ－ｅｌｅｃｔｒｏｍａｇｎｅｔｉｃｒａｄｉａｔｉｏｎｐｒｅｃ... 相似文献
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EXPERIMENT STUDY ON ACOUSTIC EMISSION,MICROSEISM AND CHARGE INDUCTION DURING FRACTURE PROCESS OF GRANITE WITH FAULT ZONE UNDER UNIAXIAL COMPRESSION 
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下载免费PDF全文 As the rock samples will produce abnormal signals of acoustic emission, microseismic and charge signals under external loading, the waveform comprehensive monitoring devices are used to synchronously monitor acoustic emission, microseismic and charge signals during the deformation and failure process of granite with fault zone under uniaxial compression. The results show that, the granite with fault zone has obvious synchronous precursory signals of acoustic emission, microseism and charge induction in the elastic deformation stage, and has high amplitude synchronous precursory signals in the instability destruction stage. The influence of fault zone on granite samples strength is remarkable, and the uniaxial compressive strength of samples with the fault zone is greatly reduced. With the angle of the fault zone decreasing, the uniaxial compressive strength of the specimens is reduced, the samples are more liable to instability and the energy of instability destruction is greater. With the fault zone angle of granite samples decreasing, the acoustic emission, microseismic and charge induction signals increase in the deformation and failure process of samples. The samples stress decreases when the acoustic emission, microseismic and charge induction precursory signals appear synchronously. The duration of acoustic emission, microseismic and charge induction precursory signals is increasing in the instability destruction stage. When the angle of the fault zone reaches 30°, the mutability of acoustic emission, microseismic and charge induction signal increases, the time to enter the dangerous stage is much earlier, and the acoustic emission events of large magnitude increase significantly, and the large angle faults of coal mine are more dangerous. The intensive and high amplitude synchronous precursory signals of acoustic emission, microseism and charge induction are produced before the instability destruction, and the signals duration is shorter. The intensive and strongest synchronous precursory signals of acoustic emission, microseism and charge induction are produced in the instability destruction, and the signals duration is longer. Acoustic emission monitoring data can better reflect the micro rupture of rock. And combined with the acoustic emission, microseismic and charge induction precursory signals, the precursory information of rock instability destruction can be obtained more accurately. 相似文献
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The influencing factors and mechanisms of the electromagnetic radiation during rock fracture 总被引：4，自引：0，他引：4
ＴｈｅｉｎｆｌｕｅｎｃｉｎｇｆａｃｔｏｒｓａｎｄｍｅｃｈａｎｉｓｍｓｏｆｔｈｅｅｌｅｃｔｒｏｍａｇｎｅｔｉｃｒａｄｉａｔｉｏｎｄｕｒｉｎｇｒｏｃｋｆｒａｃｔｕｒｅＹＵ－ＺＨＯＮＬＩＵ１）（刘煜洲）ＹＩＮＬＩＵ１）（刘因）ＹＩＮ－ＳＨＥＮＧＷＡＮＧ２... 相似文献
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Experimental study of ultralong wave band for electro－magnetic signals and acoustic emission during rock fracture 总被引：1，自引：0，他引：1
Ｅｘｐｅｒｉｍｅｎｔａｌ ｓｔｕｄｙ ｏｆ ｕｌｔｒａｌｏｎｇ ｗａｖｅ ｂａｎｄ ｆｏｒ ｅｌｅｃｔｒｏ－ｍａｇｎｅｔｉｃ ｓｉｇｎａｌｓ ａｎｄ ａｃｏｕｓｔｉｃ ｅｍｉｓｓｉｏｎ ｄｕｒｉｎｇ ｒｏｃｋ ｆｒａｃｔｕｒｅ（曹惠馨）（钱书清）（吕... 相似文献
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加卸载响应比(LURR)理论的实验研究 总被引：13，自引：1，他引：13
利用大尺度岩石试件破坏声发射实验，对加卸载响应比(Load/Unload Response Ratio)理论进行了实验研究。实验采用的加载条件力求能够模拟地下岩石的复杂受力过程。在加载过程中，岩石试件内部出现的损伤用声发射技术进行了记录。实验数据经过分析之后所得的结论与加卸载响应比理论预测的结果相符合。把加卸载响应比值Y的变化情况与声发射事件定位的过程相对比，也可以进一步看出岩石材料内部的损伤发展过程与加卸载响应比Y值的变化具有一致性。而高Y值的异常情况出现，又是在材料发生最终破坏之前，所以，可以用加卸载响应比理论定量地分析岩石试件损伤演化情况，从而对岩石材料的破坏及地震做出预测。实验结果再一次验证了加卸载响应比理论。 相似文献
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Yu Huai-zhong Yin Xiang-chu Xia Meng-fen Xu Zhao-yong Li Min Liang Nai-gang Peng Ke-yin Victor Kukshenko Wu Zhi-shen Li Qi Surguei Elizarov 《地震学报(英文版)》2004,17(1):129-137
According to the critical point hypothesis (CPH), energy release would accelerate in power law before occurrence of large
earthquakes or failure of brittle materials. In the paper, CPH was studied by acoustic emission experiments of large-scale
rock samples. Three kinds of rock samples were used in the experiments. The tri-axial loading condition was applied under
different loading histories. The released elastic energy (Acoustic emission) was recorded with acoustic emission technique
as microcracks emerged and developed inside the rock samples. The experimental results gave a further verification on the
CPH. The elastic energy release of rock samples would accelerate before the failure even under different experimental conditions.
Primary studies were also made on medium-term earthquake prediction by using accelerating energy release (AER) in the paper.
Foundation item: Project of Natural Sciences Foundation of China (10232050), Project of State Key Basic Research (2002CB412706) and Project
of Computer Network Information Center, Chinese Academy of Sciences (2002CB412706). 相似文献